More icebergs are adrift in the Southern Ocean

One of the effects of global warming has been an increase in icebergs breaking off from the Antarctic ice sheet. Oceanographers studying this phenomenon learned that free-drifting Antarctic icebergs can make important positive contributions to the carbon cycle in the Southern Ocean that is so important to a balanced planet, according to a new report.

Iceberg W-86 in December 2005 in the Weddell Sea.
(Image courtesy of Henry A. Ruhl)

These icebergs can be as small as meters in diameter, or as large as hundreds of kilometers across. Oceanographers led by Ken Smith, Jr. at the Monterey Bay Aquarium Research Institute wanted to determine if the icebergs influenced the open sea ecosystem.

He and his colleagues studied two drifting icebergs and the surrounding waters, in the Weddell Sea in 2005. They found land-based material, chlorophyll, krill and seabirds were more abundant around the icebergs and up to about 4 kilometers away than in areas with no icebergs. The researchers detected 89 icebergs of similar size in the general area and calculated that about 40 percent of the surface water was influenced by melting, drifting ice.

The authors suggest that this type of iceberg will become more widespread as warming and iceberg production rates increase.

"Our planet is rapidly changing with global warming,” Smith said. “Our oceans, the largest and most influential part of earth, require constant long term monitoring.”

About the scientist

Ken Smith works as an oceanographer. His interests were in the area of athletics until he was inspired by a zoology professor in his freshman year at college. “Science has been my passion even since,” he said.